/***************************************************************************/
/*                                                                         */
/*  gxvmort4.c                                                             */
/*                                                                         */
/*    TrueTypeGX/AAT mort table validation                                 */
/*    body for type4 (Non-Contextual Glyph Substitution) subtable.         */
/*                                                                         */
/*  Copyright 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K.,       */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/

/***************************************************************************/
/*                                                                         */
/* gxvalid is derived from both gxlayout module and otvalid module.        */
/* Development of gxlayout is supported by the Information-technology      */
/* Promotion Agency(IPA), Japan.                                           */
/*                                                                         */
/***************************************************************************/


#include "gxvmort.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT trace_gxvmort


static void
gxv_mort_subtable_type4_lookupval_validate(FT_UShort glyph,
                                           GXV_LookupValueCPtr value_p,
                                           GXV_Validator valid)
{
    FT_UNUSED(glyph);

    gxv_glyphid_validate(value_p->u, valid);
}

/*
 +===============+ --------+
 | lookup header |         |
 +===============+         |
 | BinSrchHeader |         |
 +===============+         |
 | lastGlyph[0]  |         |
 +---------------+         |
 | firstGlyph[0] |         |    head of lookup table
 +---------------+         |             +
 | offset[0]     |    ->   |          offset            [byte]
 +===============+         |             +
 | lastGlyph[1]  |         | (glyphID - firstGlyph) * 2 [byte]
 +---------------+         |
 | firstGlyph[1] |         |
 +---------------+         |
 | offset[1]     |         |
 +===============+         |
 |
   ....                     |
 |
   16bit value array         |
 +===============+         |
 |     value     | <-------+
   ....
 */

static GXV_LookupValueDesc
gxv_mort_subtable_type4_lookupfmt4_transit(
    FT_UShort relative_gindex,
    GXV_LookupValueCPtr base_value_p,
    FT_Bytes lookuptbl_limit,
    GXV_Validator valid)
{
    FT_Bytes p;
    FT_Bytes limit;
    FT_UShort offset;
    GXV_LookupValueDesc value;

    /* XXX: check range? */
    offset = (FT_UShort)(base_value_p->u +
                         relative_gindex * sizeof(FT_UShort));

    p = valid->lookuptbl_head + offset;
    limit = lookuptbl_limit;

    GXV_LIMIT_CHECK(2);
    value.u = FT_NEXT_USHORT(p);

    return value;
}


FT_LOCAL_DEF(void)
gxv_mort_subtable_type4_validate(FT_Bytes table,
                                 FT_Bytes limit,
                                 GXV_Validator valid)
{
    FT_Bytes p = table;


    GXV_NAME_ENTER("mort chain subtable type4 "
                   "(Non-Contextual Glyph Substitution)");

    valid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED;
    valid->lookupval_func = gxv_mort_subtable_type4_lookupval_validate;
    valid->lookupfmt4_trans = gxv_mort_subtable_type4_lookupfmt4_transit;

    gxv_LookupTable_validate(p, limit, valid);

    GXV_EXIT;
}


/* END */